public int BaseStepH(ref DistanceInterpolator2 di)
 {
     m_li.Next();
     m_x += m_lp.inc;
     m_y  = (m_lp.y1 + m_li.Y) >> LineAA.SUBPIXEL_SHIFT;
     if (m_lp.inc > 0)
     {
         di.IncX(m_y - m_old_y);
     }
     else
     {
         di.DecX(m_y - m_old_y);
     }
     m_old_y = m_y;
     return(di.Distance / m_len);
 }
        public LineInterpolatorAA1(OutlineRenderer ren, LineParameters lp, int sx, int sy)
        {
            this._ren = ren;
            _aa_data  = new Lines.LineInterpolatorAAData(ren, lp);
            _m_di     = new DistanceInterpolator2(lp.x1, lp.y1, lp.x2, lp.y2, sx, sy,
                                                  lp.x1 & ~LineAA.SUBPIXEL_MARK, lp.y1 & ~LineAA.SUBPIXEL_MARK);


            int dist1_start;
            int dist2_start;
            int npix = 1;

            if (lp.vertical)
            {
                do
                {
                    _aa_data.m_li.Prev();
                    _aa_data.m_y -= lp.inc;
                    _aa_data.m_x  = (_aa_data.m_lp.x1 + _aa_data.m_li.Y) >> LineAA.SUBPIXEL_SHIFT;
                    //
                    if (lp.inc > 0)
                    {
                        _m_di.DecY(_aa_data.m_x - _aa_data.m_old_x);
                    }
                    else
                    {
                        _m_di.IncY(_aa_data.m_x - _aa_data.m_old_x);
                    }
                    //
                    _aa_data.m_old_x = _aa_data.m_x;
                    dist1_start      = dist2_start = _m_di.DistanceStart;
                    int dx = 0;
                    if (dist1_start < 0)
                    {
                        ++npix;
                    }
                    do
                    {
                        dist1_start += _m_di.DyStart;
                        dist2_start -= _m_di.DyStart;
                        if (dist1_start < 0)
                        {
                            ++npix;
                        }
                        if (dist2_start < 0)
                        {
                            ++npix;
                        }
                        ++dx;
                    }while (_aa_data.m_dist[dx] <= _aa_data.m_width);
                    --_aa_data.m_step;
                    if (npix == 0)
                    {
                        break;
                    }
                    npix = 0;
                }while (_aa_data.m_step >= -_aa_data.m_max_extent);
            }
            else
            {
                do
                {
                    _aa_data.m_li.Prev();
                    _aa_data.m_x -= lp.inc;
                    _aa_data.m_y  = (_aa_data.m_lp.y1 + _aa_data.m_li.Y) >> LineAA.SUBPIXEL_SHIFT;
                    //
                    if (lp.inc > 0)
                    {
                        _m_di.DecX(_aa_data.m_y - _aa_data.m_old_y);
                    }
                    else
                    {
                        _m_di.IncX(_aa_data.m_y - _aa_data.m_old_y);
                    }
                    //
                    _aa_data.m_old_y = _aa_data.m_y;
                    dist1_start      = dist2_start = _m_di.DistanceStart;
                    int dy = 0;
                    if (dist1_start < 0)
                    {
                        ++npix;
                    }
                    do
                    {
                        dist1_start -= _m_di.DxStart;
                        dist2_start += _m_di.DxStart;
                        if (dist1_start < 0)
                        {
                            ++npix;
                        }
                        if (dist2_start < 0)
                        {
                            ++npix;
                        }
                        ++dy;
                    }while (_aa_data.m_dist[dy] <= _aa_data.m_width);
                    --_aa_data.m_step;
                    if (npix == 0)
                    {
                        break;
                    }
                    npix = 0;
                }while (_aa_data.m_step >= -_aa_data.m_max_extent);
            }
            _aa_data.m_li.adjust_forward();
        }